Blizzard has posted a message in response to the perception that recent reports of account hacking in Diablo III represent an uptick in such incidents. They say the number of compromised accounts does not represent anything unusual for their games, and that they continue to recommend the use of the Battle.net Authenticator or the Battle.net Mobile Authenticator for best security of your Battle.net account:

We'd like to take a moment to address the recent reports that suggested that Battle.net® and Diablo® III may have been compromised. Historically, the release of a new game -- such as a World of Warcraft® expansion -- will result in an increase in reports of individual account compromises, and that's exactly what we're seeing now with Diablo III. We know how frustrating it can be to become the victim of account theft, and as always, we're dedicated to doing everything we can to help our players keep their Battle.net accounts safe -- and we appreciate everyone who's doing their part to help protect their accounts as well. You can read about ways to help keep your account secure, along with some of the internal and external measures we have in place to help us achieve our security goals, at our account security website here: www.battle.net/security.

We also wanted to reassure you that the Battle.net Authenticator and Battle.net Mobile Authenticator (a free app for iPhone and Android devices) continue to be some of the most effective measures we offer to help players protect themselves against account compromises, and we encourage everyone to take advantage of them. In addition, we also recently introduced a new service called Battle.net SMS Protect, which allows you to use your text-enabled cell phone to unlock a locked Battle.net account, recover your account name, approve a password reset, or remove a lost Authenticator. Optionally, you can set up the Battle.net SMS Protect system to send you a text message whenever unusual activity is detected on your account, keeping you aware of important (and possibly unwanted) changes.

We also have other measures built into Battle.net to help protect players. Occasionally, when Battle.net detects unusual login activity that differs from your normal behavior -- such as logging in from an unfamiliar location -- we may prompt you for additional information (such as the answer to one of your security questions) and/or require you to perform a password reset through the Battle.net website. World of Warcraft players might be familiar with this security method already, and Diablo III players may begin to encounter it as well.

Creston wrote on May 22, 2012, 22:40:Yeah, hackers have just managed to brute force thousands of people's of passwords all in one week. There's nothing else going on, just pure sheer luck.

Who says that they did it in a week? These are battle.net accounts, not Diablo III accounts. Blizzard announced you can turn bits into cash a long time ago, while WoW gold has been becoming less and less valuable. Smart hackers have been building up a stock of compromised accounts for a while now, just waiting for Diablo III to go live.

What people are seeing now is, likely as not, months worth of hacked accounts being accessed for the first time all at once.

/edit - and seriously, people using "ABC123" as their password and downloading porn aps isn't a Blizzard security issue.

Still, with these people playing D3, they are most likely playing daily since its so new and there are suddenly many accounts being hacked by players in many different places, their system should notice that someone shouldn't being logging in from another state within an hour our two. And with so many accounts they most likely are coming from the same IP area which should set off warning bells when a few hundred accounts suddenly all stop logging in from their last known IP and suddenly are logging in from the same IP area, which the same computer specs that doesn't match their last known configuration (something the warden program is supposed to look at)